1. Field of the Invention
The present invention generally relates to an image-forming device, such as a copying machine utilizing electrophotography, a facsimile, and a printer, and more particularly, to an image-forming device including process regulating means for regulating an image-forming electric potential formed on a latent image on an image-bearing member, and for regulating a toner density of a developer to form a toner image of the latent image, etc.
2. Description of the Related Art
In general, an image-forming device of this type comprises various types of image-forming means, such as a photosensitive member functioning as an image-bearing member, an electrifying device electrifying the photosensitive member, an exposing device forming a latent image on the electrified photosensitive member, a developing device developing the latent image on the photosensitive member so as to form a toner image on the photosensitive member, a transferring device transferring the toner image formed on the photosensitive member to a recording paper functioning as a recording medium, a cleaning device removing a residual toner on the photosensitive member after transferring, and a fixing device fixing the transferred toner image on the recording paper.
Further, in order to form an output image of a targeted quality, the image-forming device of this type conventionally performs various process regulations, such as an image-forming-potential regulation for regulating an image-forming electric potential of the latent image formed on the photosensitive member, and a toner-supplement regulation for adjusting a toner density of the developer used to form the toner image from the latent image.
The above-mentioned toner-supplement regulation is performed, for example, as follows.
First, as shown in FIG. 1 and FIG. 2, a plurality (three in the figures) of latent image patterns 20a, 20b and 20c at predetermined electric potentials are formed on a photosensitive member 20.
Next, an infrared light is projected from a toner-amount detecting sensor 25 to the photosensitive member 20 so as to detect the amount of toner attached on the latent image patterns 20a, 20b and 20c. 
The toner-amount detecting sensor 25 comprises a light-emitting element 25a emitting the infrared light, and a light-receiving element 25b receiving a regular reflected light (a light beam having a reflection angle equal to an incident angle) of the infrared light, as shown in FIG. 2.
The toner-amount detecting sensor 25 detects whether or not the amount of the toner attached on the latent image patterns 20a, 20b and 20c is equal to a targeted amount of toner corresponding to a desired output image, on the basis of a luminous energy of the regular reflected light received by the light-receiving element 25b. When the luminous energy of the regular reflected light received by the light-receiving element 25b is large, i.e., when the amount of the toner attached on the latent image patterns 20a, 20b and 20c is insufficient, a toner supplement signal is output from the light-receiving element 25b. 
Then, when the toner supplement signal is output from the light-receiving element 25b, a proper amount of toner is supplemented from a toner-supplementing device (not shown in the figures) to the above-mentioned developing device. Thereby, the toner density of the developer supplied from the developing device is made appropriate so that the amount of the attached toner of the toner image formed on the photosensitive member 20 becomes an amount that can achieve a targeted quality of the desired output image.
On the other hand, the above-mentioned image-forming-potential regulation is performed, for example, as follows.
First, as shown in FIG. 3, a plurality (three in the figure) of patterned latent images at electric potentials different from one another by increasing degrees are formed on the photosensitive member 20, and are developed by using a toner so that latent image patterns 30a, 30b and 30c having different toner densities are formed on the photosensitive member 20.
Next, a development characteristic (a development xcex3) of the above-mentioned developing device is calculated from the relationship between the amount of toner attached on the latent image patterns 30a, 30b and 30c and the surface potential of the latent image patterns 30a, 30b and 30c detected by a potential sensor (not shown in the figure). A grid voltage of the above-mentioned electrifying device, a development bias of the above-mentioned developing device, and an LD (a laser luminescence) power of the above-mentioned exposing device, etc. are regulated so that the amount of the toner attached on the latent image patterns 30a, 30b and 30c becomes equal to a targeted amount of toner. Thereby, the electric potential to form the toner image on the photosensitive member 20 is optimized so that the amount of the attached toner of the toner image becomes an amount that can achieve a targeted quality of a desired output image.
Thus, it is supposed that, in the image-forming device of this type, if the toner density of the developer supplied from the developing device and the electric potential to form the toner image on the photosensitive member 20 are optimized by the above-described toner-supplement regulation and the image-forming-potential regulation, the amount of the attached toner of the toner image is maintained in an ideal condition that can achieve the targeted quality of the desired output image.
In reality, however, the image-forming device of this type performs an image formation in various cases as follows: the toner image is formed only by a developer of a particular color; an image area is extremely small; a normal image formation is hardly performed, and therefore, only an automatic regulation is performed in which the toner supplementation by the above-mentioned image-forming-potential regulation, etc. is not performed. At this point, normally in the above-mentioned toner-supplement regulation, when the toner image is not formed on the photosensitive member 20, no toner is supplemented from the above-mentioned toner-supplementing device to the above-mentioned developing device. Therefore, when the development capability (a capability of developing the latent image) of the developing device is either higher or lower than a standard level, there occurs a problem that the image-forming potential-regulation alone cannot sufficiently regulate the amount of the attached toner of the toner image.
In order to solve this problem, there is a conventional image-forming device performing a so-called self-check, in which a toner is supplemented to the above-mentioned developing device; or a toner is consumed in the developing device, at a predetermined timing, so as to adjust the toner density of the developer supplied from the developing device, and thereafter, the above-mentioned image-forming-potential regulation is performed.
The image-forming-potential regulation in this image-forming device is performed as a special job at a timing different from an image-forming routine of a normal toner image. For example, the image-forming-potential regulation is performed, for example, immediately after electric power is supplied to the image-forming device having the above-mentioned fixing device in a cool state, after an image-forming job is performed predetermined times, or after a predetermined time has passed since the previous image-forming-potential regulation.
The special job for the self-check as mentioned above is effective in maintaining an image quality. Especially, in a color-image forming device, the process regulations are made more stable by performing various regulations, as described above, based on plenty of information in a sufficient period of time for each color.
However, in an image-forming device structured so as to perform the special job for the self-check as mentioned above, various regulations are performed in the special job, based on plenty of information in a sufficient period of time for each color. This results in a problem that a user cannot use this image-forming device to conduct an image-formation during a predetermined time in which the regulations are performed.
Conventionally, in consideration of such an operability for the user, the special job is performed using a period of time in which the fixing device warms up upon supplying electric power to the image-forming device for the day. However, a recent image-forming device is required to have a shortened start-up time; therefore, it is difficult to secure a sufficient period of time to perform the special job.
Additionally, an image-forming device installed in a convenience store, for example, is frequently used while electric power is kept supplied 24 hours a day. With respect to this image-forming device, there is a problem that a user has no time or place to wait for the special job to be performed.
It is a general object of the present invention to provide an improved and useful image-forming device in which the above-mentioned problems are eliminated.
A more specific object of the present invention is to provide an image-forming device which can perform a self-check in a shortened period of time while maintaining a targeted image quality.
In order to achieve the above-mentioned objects, there is provided according to one aspect of the present invention an image-forming device comprising:
information-detecting means for detecting information A regarding first processing means and information B regarding second processing means; and
judging means for judging, according to the information A, whether or not a regulation of the first processing means needs to be performed,
wherein, when the judging means judges that the regulation of the first processing means needs to be performed, a first regulation mode is performed in which the regulation of the first processing means is performed, the information-detecting means detects at least the information B, and a regulation of the second processing means is performed according to the information B, and
when the judging means judges that the regulation of the first processing means does not need to be performed, a second regulation mode is performed in which the first regulation mode is not performed, and the regulation of the second processing means is performed according to the information B.
In the image-forming device according to the present invention, when the judging means judges that the regulation of the first processing means does not need to be performed, the regulation of the first processing means is not performed, and the information-detecting means does not detect the information B once again. Accordingly, the image-forming device according to the present invention can perform the process regulations as above in a shortened period of time when the judging means judges that the regulation of the first processing means does not need to be performed.
Additionally, in the image-forming device according to the present invention, the information A may regard a toner-density regulation regulating a toner density of-developing means functioning as the first processing means, and
the information B may regard at least one of an electrification potential of electrifying means, a write luminous energy of image-writing means, and a developing bias of the developing means, the electrifying means, the image-writing means, and the developing means functioning as the second processing means.
Additionally, in the image-forming device according to the present invention, the developing means may comprise a plurality of developing devices respectively containing toners of a plurality of colors.
In the image-forming device according to the present invention, when the judging means judges that the toner-density regulation of the developing means does not need to be performed, the toner-density regulation of the developing means is not performed, and the information-detecting means does not detect the information B once again. Accordingly, the image-forming device according to the present invention can perform the process regulations as above in a shortened period of time when the judging means judges that the toner-density regulation of the developing means does not need to be performed.
In order to achieve the above-mentioned objects, there is also provided according to another aspect of the present invention an image-forming device comprising:
information-detecting means for detecting information A regarding a toner-density regulation of a plurality of developing devices and information B regarding at least one of an electrification potential of electrifying means, a write luminous energy of image-writing means, and a developing bias of each of the developing devices; and
judging means for judging, according to the information A, whether or not the toner-density regulation of each of the developing devices needs to be performed,
wherein, when the judging means judges that the toner-density regulation of one of the developing devices needs to be performed, a first regulation mode is performed in which the toner-density regulation of the one of the developing devices is performed, the information-detecting means again detects at least the information B with respect to the one of the developing devices, and a regulation of at least one of the electrification potential of the electrifying means, the write luminous energy of the image-writing means, and the developing bias of the one of the developing devices is performed according to the information B, and
when the judging means judges that the toner-density regulation of one of the developing devices does not need to be performed, a second regulation mode is performed in which the first regulation mode is not performed with respect to the one of the developing devices, and the regulation of at least one of the electrification potential of the electrifying means, the write luminous energy of the image-writing means, and the developing bias of the one of the developing devices is performed according to the information B.
In the image-forming device according to the present invention, when the judging means judges that the toner-density regulation of a particular one of the developing devices does not need to be performed, the first regulation mode is not performed with respect to the particular developing device. In other words, when the judging means judges that the toner-density regulation of a particular one of the developing devices needs to be performed, the first regulation mode is performed with respect to the particular developing device. Thereby, even when the judging means judges that the toner-density regulation does not need to be performed for the first developing device, for example, the judging means surely judges whether to perform the toner-density regulation with respect to the other developing devices without erroneously skipping those judgments and proceeding to the process regulations. Besides, when it is arranged that the information-detecting means detects the information by sensing latent image patterns formed on an image-bearing member, the latent image patterns do not need to be re-formed to sense the latent image patterns again, when the judging means judges that the toner-density regulation of the particular developing device does not need to be performed. This prevents the toner from being wastefully consumed.
Additionally, in the image-forming device according to the present invention, each of the developing devices may be moved to a predetermined position so as to perform an image-development, and
the judging means may judge, according to the information A, whether or not the toner-density regulation of each of the developing devices moved to the predetermined position needs to be performed, and successively, when the judging means judges that the toner-density regulation of one of the developing devices moved to the predetermined position needs to be performed, the toner-density regulation of the one of the developing devices may be performed.
In the image-forming device according to the present invention, the judging operation and the toner density regulation are performed in succession when the judging means judges that the toner-density regulation needs to be performed with respect to one of the developing devices moved to the predetermined position. Thereby, the developing devices do not have to be moved to the development position between the judging operation and the toner density regulation. This minimizes a time required for shifting the developing devices to the development position. Thus, the image-forming device according to the present invention can perform the process regulations as above in a shortened period of time.
Other objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings.